[Vestibulocochlear syndrome in lesions of the midbrain]

Abstract

Midbrain affection can be evidenced by pronounced central cochleovestibular syndrome which presents with converging spontaneous nystagmus, elements of monocular nystagmus, early impairment of optokinetic nystagmus in all the directions, bilateral neurosensory hypoacusis, a dramatic decrease of speech intelligibility in several sound sources, disturbed binaural hearing in normal or symmetrically reduced hearing, the absence of sound lateralization in Weber test under acute hearing asymmetry or unilateral deafness. Midbrain tumors are characterized by early hypertensive otoneurological syndrome indicated by caloric nystagmus of longer duration and greater tonicity. One case of midbrain lesion is detailed.